Rotary top brushes have been used for some time in mechanized vehicle wash systems. Typically, such a rotary top brush is mounted on a horizontal shaft and spans substantially the width of the vehicle. Relative vertical and longitudinal movement between the top brush shaft and vehicle enables the top brush to move over the grill, hood, windshield, top and trunk of the vehicle for cleaning same.
A primary difficulty encountered in prior rotary top brushes has been lack of adequate bristle lubrication, that is, lubrication of the entire length of the bristle strands, from mounted end to free end. The term lubricating liquid refers, for example, to water containing soap or detergent or water alone.
Among the problems resulting from improper bristle lubrication are the following. Without proper lubrication, the bristles drag rather than slide over the surface of the vehicle, thereby tending to wrap around, or become jammed under, trim and accessories. Thus, trim and accessories such as mirrors, bright metal trim strips and the like are readily damaged or ripped off the vehicle by the bristles.
Further, certain accessory parts, notably aerials, which penetrate a substantial distance into the bristled portion of the brush, tend to be entangled or enwrapped by the relatively long flexible bristles. Improperly lubricated bristles will not readily release and may damage or break off the aerial. Still further, surfaces of the vehicle will be repeatedly contacted during the washing by rapidly moving bristles, and inadequately lubricated bristles tend to damage the finish of the vehicle. More particularly, the surface of the vehicle is frequently marked or hazed by deposits thereon of a wax-like film (e.g. polyolifin) from the brush bristles or may be actually scratched by bristles which have picked up dirt particles or road film and are continually slapping or rubbing against the car finish at high speeds.
Moreover, improper lubrication increases bristle wear and decreases bristle life. Additionally, improper bristle lubrication causes the brush to clean less well. Other disadvantages of improper lubrication exist but are not believed to require discussion.
Attempts to supply liquid lubricant to brushes of this kind by spraying from an external nozzle onto the periphery of the rotating brush have not been satisfactory. The rotating brush bristles tend to bat away, or throw off, the lubricant so applied. This is especially true when brush rotational rate and/or diameter is sufficient to create high bristle tip speed, as is normally the case for a top brush in car wash systems. The result is that the lubricant does not penetrate the brush, being present at best merely on the exposed bristle tips and leaving the major bristle length substantially unlubricated. Attempts to increase the flow rate of liquid lubricant to the brush have been ineffective and, indeed have increased cost through use of more lubricant.
Thus, while rotating top brushes have been known for some time in vehicle washing systems, the above mentioned difficulties have been sufficient to cause some car wash owners not to use their top brush at all, even in the face of higher labor costs. Attempts to utilize a nonrotating top cleaning device, such as a nonrotatable brush or piece of carpet fabric which is dragged over the surface of the vehicle, have generally provided unsatisfactory cleaning.
A prior attempt to provide lubricant to a rotatable top brush by means of a hollow top brush shaft was unsuccessful in that liquid could not be provided with sufficient uniformity or in sufficient amount for satisfactory brush lubrication.
The problem of rotary top brush lubrication is complicated by such characteristics as substantial brush size (a 5 foot diameter and 6 foot length being common), need for relatively small core diameter, and high bristle tip speeds. Further compounding the problems are restrictions on noise generated by drying blowers utilized in such vehicle washing systems as a result of Occupational Health and Safety Administration rules. Such restrictions have resulted in reduced dryer-blower speeds and hence have forced use of higher heat settings for dryer heating elements. This excessively heats and dries the bristles of the adjacent top brush and further increases the need for effective lubrication of the top brush.
Accordingly, the objects and purposes of this invention include provision of:
1. A rotary brush construction particularly for vehicle washing in which the bristles are lubricated along the lengths thereof from point of attachment to the rotary brush core to the free ends, or tips, thereof.
2. A brush construction, as aforesaid, wherein proper lubrication is maintained despite substantial overall brush diameter, substantial brush length and relatively high bristle tip speeds.
3. A brush construction, as aforesaid, capable of satisfactory cleaning of vehicle surfaces without marking, hazing or scratching thereof, and particularly wherein the brush bristles do not tend to pick up dirt particles or road film or scratch the vehicle finish therewith or deposit a waxlike film thereon.
4. A brush construction, as aforesaid, wherein bristle drag on vehicle surfaces is substantially reduced and wherein the bristles tend to slide easily over vehicle surfaces encountered thereby.
5. A brush construction, as aforesaid, wherein brush bristles no longer tend to wrap around or jam under vehicle accessories such as mirrors, chrome strips and the like and wherein the brush bristles no longer tend to damage or rip off projecting accessories on the vehicle.
6. A brush construction, as aforesaid, in which entanglement of brush bristles with, and damage to, aerials or the like is substantially reduced despite deep penetration of such aerials or the like into the bristle field of the brush.
7. A brush construction, as aforesaid, in which effective cleaning is acheived with moderate amounts of liquid lubricant and wherein shortening of brush life due to premature bristle wear is avoided.
8. A brush construction, as aforesaid, in which effective lubrication of the bristles is provided even under conditions of high heat and wherein centrifugal force generated by brush rotation is utilized to aid distribution of liquid lubricant along the length of the bristles from root to tip and so as to provide a constant flushing of the bristles.
9. A brush construction, as aforesaid, which is of relatively simple construction and is readily manufacturable from available materials and at costs generally comparable to existing top brushes.
10. A brush construction, as aforesaid, enabling rapid and simple replacement of worn portions of the brush construction without disturbing securement of remaining portions of the brush construction on the brush shaft and wherein different length sections of the brush construction may be provided with differing and readily variable bristle densities.